Open hole removable packer



July 4, 1944. A. T. FERRlS OPEN HOLE REMOVABLE PACKER Filed Jan. 28,1942 INVENTOR AUTTIE T. FERRIS Patented July 4, 1944 v UNITED STATESPATENT OFFICE orim' HOLE amovsnu: racxaa Anttie T. Ferris, Flora, 111.,assignor to Halllbar- 8:. Oil Well cementing Company. Duncan,

Applicationlanuary as, 1942, Serial No. 42am 1 mm' (01. 166-42) Thisinvention relates to packers adapted for use in oil wells, and moreparticularly to packers adapted to be secured in the open or uncasedportion .of an oil well to eilect a seal therein and to prevent fluidunder pressure from moving past outside of the tubing. As commonlypracticed heretofore, the cement has been prevented from moving upwardlyon the outside of the tubing by means of a cement retainer set by meansof slips to casing in the well. It is sometimes desirable, however, tocement oil a formation some distancebelow the shoe of the casing whilepreventing the flow ofcement into another formation below the shoe ofthe casing but above the formation being cemented. The presentarrangement, wherein the packer is set and secured in the open holebeneath the shoe of the casing and designed to engage the wall of thewell in an uncased portion thereof and special means is proso arrangedas to withstand considerable pressure, is intended to solve thisproblem. 7

Packers of the type herein shown and described may also be used toadvantage in connection with the acidizing of oil wells. They areparticularly adapted for use in connection with combination acidizingand cementing operations oi the type shown, described and claimed in theUnited States patent to William D. Owsley, et al., No. 2.163.449, forMethod of treating a well, granted June 20, 1939.

In the United States patent to O'Donnell, No. 2.204.378, granted June11, 1940, an open hole packer similar to that of the present arrangementis shown and described, but the O'Donnell packer has'certaindisadvantages in that it requires the use of an anchor pipe which restson i the bottom of the well to support the lower shoe of the packer, andin that it cannot be removed from the well once it is set, except bydrilling it up. 7

vided for efl'ecting a seal beneaththe slips.

Accordingly. it is one object of the invention to devise a novelcombination of elements which -co-act in such a way as to provide anopen-hole packer which can be set and released so that it may be removedfrom the well without the necessity of drilling it up.

It is a further object of the invention to devise novel means forsetting and holding a pack er in an uncased part of an oil well, whichmeans can be so manipulated that the packer can be released at any time,such as after cement has been placed and hardened therebeneath, so thatthe packer can be removed from the well or moved to another point in thewell.

Other objects and advantages reside in certain novel features of thearrangement and construction of parts, as will be apparent from thefollowing description taken in, connection with the accompanyingdrawing, in which;

Figure 1 is a vertical quarter-sectional view of an open hole packerconstructed in accordance with the principals of the present invention,the view showing the relative position of the parts when the packer isnot set and as it is being lowered into a well: and

Figure 2 is a vertical quarter-sectional view of the same apparatus asthat shown in Figure 1, but with the parts in the position which theytake when the packer is set.

Referring to the drawing in detail, it will be seen that an oil welltubing is shown at i i, upon which the apparatus of the presentinvention is adapted to be lowered into an oil well. Between the tubingii and the packer assembly, a circuiating valve or sub I2 is provided.As illustrated, this sub may be the same as that shown and described inthe patent to Halliburton, No. @235,- 318, granted March 18, 1941.

Connected to the lower end of the circulating sub by the safety jointcoupling i3, there is a slip The present invention relates toimprovements in open hole packers such as that disclosed in theO'Donnell patent referred to, by which the above-mentioned disadvantagesare eliminated. The anchor pipe is entirely eliminated and slips areemployed to grip the wall of the well. and.

provision is made for releasing the slips when desired. The wickers oithe slips are especially body H, upon which especially designed slips iiare mounted for limited radial movement in recesses contained in theslip body It. Inserted in the recesses behind the slips are slip padsIt. These pads are, in general, rectangular in shape 'and have adepression or cupped portion on one face. They may be made of rubberreinforced with fabric. These slip pads act as, packing and prevent anyfluid from passing around the slip are ports ll in the slip body I whichconnect the passageway I! to the recesses beneath the pads l6. Thus, bypumping a fluid down through the tubin pressure may be transmitted intothe space behind the slip pads and if the pressure on the outside of theslip body is less than that on the interior, the slip pads will act aspistons to force the slips out against the wall of the bore hole. Leafsprings I! connected by screws to the sli body I provide means forholding the slips in the retracted position shown in Figure 1, while theapparatus is being lowered into the well and also serve to urge theslips back into the slip body afterthey have been forced outwardlywhenever the pressure on the interior and exterior of the slip body isequalized.

The slips I! are especially designed to adapt them to engage and hold inopen hole formations in oil wells. The wickers of the slips are largerand have sharper edges than those of slips commonly used in oil wellsfor engaging casing or the like and it has been discovered that if theformation opposite the slips is relatively hard, such as limestone,these slips will serve to hold the tool against movement in the well. i

A hollow mandrel 20 is threaded into the lower end of the slip body I4.The upper portion of the mandrel 20 is of slightly larger diameter thanthe lower portion thereof; so as to provide a shoulder 2|.

Blidably mounted on the upper portion of the mandrel and abuttingagainst the lower surface of the slip body i4, there is a rubber wallpacker sleeve 22. As shown in Figure 1, this sleeve normally extendsdownwardly some distance below the shoulder 2i.

A slidable operating sleeve 23 is telescoped upon the lower portion ofthe mandrel 20. with its upper portion inside of the wall packer sleeve22. Integral with this operating sleeve is a lower shoe 25 for the wallpacker sleeve and also one or more rubber swab cups 25 mounted ininverted position.

The rubber wall packer sleeve and the rubber swab cups may be of theconstruction commonly employed in oil wells and in which the rubber maybe reinforced with fabric or the like.

To limit movement of the operating sleeve 23 longitudinally upon themandrel 20 and. also to prevent it from falling of! of the mandrel, acollar 26 is threaded onto the lower end of the 'mandrel. The lower endof the collar 26 is threaded so that a tail pipe may be connectedthereto, if desired, so that fluid may be discharged from the tool atany desired distance beneath the tool when the packer is set.

To operate the assembly shown in the drawing in carrying out a cementingoperation, the tool is lowered into the well on the tubing H. with theparts in the position shown in Figure 1. With the parts in this positionthere is no tendency for the slips to engage the wall of the hole or forthe wall packer sleeve to expand, because the pressure above and belowthe swab cups 25 is substantially the same, due to the fact that thecirculating sub i2 is open, so that fluid can flow from a point beneaththe tool upwardly through the mandrel 20, the passage I! in the slipbody M, the safety joint i3 and out through the ports in t e circulatingsub or on up into the tubing Ii. In this way the hydrostatic head insidethe tubing ii is the same as that on the outside.

When the tool has men lowered to the desired point in the well where itis desired that a seal be eflected, the circulating sub i2 is closed bymerely picking up or lifting the tubing ii a short distance. Fluid isthen pumped down through the tubing i l and through the entire tool,discharging through the collar 28.

The swab cups 2! are incapable of forming a complete seal with the wallof the bore hole but they do oiler suihcien't impedance to the flow offluid upwardly around the outside of the tool to maintain a slightpressure differential and as a result, hydrostatic pressure istransmitted to the slip pads it, which causes the slips. to expand andIf the tubing II is filled with mud, as is normally the case in acementing operation, it is necessary to remove the mud before squeezingcement into the formation beneath the tool. This can be done byreleasing the fluid pressure in the tubing ll, so that the packer andslips collapse, then lowering the tubing slightly to open thecirculating sub l2. Cement slurry can then be forced down through thetubing II with the mud ahead of it being displaced and moving'outthrough the circulating sub l2. When the cement slurry is down nearly tothe depth of the tool, the circulating sub may be closed and pressureapplied. The application of pressure will again set the slips and packeras described above, and cause the cement to be squeezed into theformation beneath the tool. As soon as the cement slurry is in place,circulation of mud in the reverse direction, that is, down on theoutside of the tubing and up through the interior, may be brought about.

If the circulating sub is held closed, reverse circulation of mud willwash out the tool, the mud flowing downwardly past the slips, the packer22 and the swab cups 25 and up through the interior of the tool into thetubing. This action is possible because as soon as the pressure on theexterior of the tool is the same as that on the interior, the slips andwall packer sleeve take the retracted or collapsed position shown inFigure 1.

As mentioned above, the apparatus shown and described may also be usedwith success in carrying on acidizing operations in oil wells where itis desired to effect a seal at a particular point in the uncased part ofthe well.

To explain this operation, a typical instance of the use of the tool inIllinois will be described. The well was equipped with casing cementedat a depth of approximately 3,390 feet. The total depth of the well wasreported to be 3,440 feet and plugged back to a depth of 3,478 feet. Theamount of open hole was calculated to be approximately 50 feet, theproduction belng in limestone which it was desired to treat with 1,000gallons of 15% hydrochloric acid.- The apparatus shown and describedherein was set in the well opposite a hard lime section at a depth of3,425 feet. A perforated pipe 11 feet long was connected to the coupling26, being located at a depth of 3.427 to 3,438 feet, which was reportedthe slips and packer were set. Acid was then pumped into the McCloskylime formation at an initial pressure of 500 pounds per square inch.After 1 hour and 20 minutes, 500 gallons of acid had been pumped intothe formation and the pump pressure had increased to 1,000 pounds persquare inch. The pressure continued to increase until it reached 2,000pounds per square inchwhen the 1,000 gallons of acid had been pumpedinto the formation. The total time of the acid displacement was 3 hoursand 45 minutes.

The annular space between the tubing and the wall of the hole. both inthe cased and uncased portion thereof, was maintained full of 011 duringthe time that pressure was maintained in forcing the acid into. theformation.

On completion of the acidizing operations, the pressure was equalizedand the tubing and the tool removed from the well.

While only one embodiment of the invention has been shown and describedherein, it is obvious that various changes may be made in thearrangement and construction of parts, without departing from. thespirit of the invention or the scope of the annexed claim.

I claim:

An open hole removable packerfor oil well or the like, adapted to belowered into a well on tubing, including a hollow mandrel adapted to be5 connected to the tubing, a set of slips means for mounting said slipsfor limited radial movement on said mandrel near its upper end, meansoperable hydraulically for actuating said slips to move the sameoutwardly to engage the wall of the 10 bore hole and prevent movement ofthe mandrel in the hole, a cylindrical wall packer sleeve mounted onsaid mandrel beneath said slips and means operable hydraulically forexpanding said sleeve to caus the same to engage the wall of iii thebore hole and efiect a seal between it and the mandrel, said means forexpanding said packer sleeve, including an operating member slidablymounted on said mandrel beneath said packer sleeve, a lower shoe forsaid packer sleeve fixed 20 to said member and aninverted swab cup fixedto said member beneath said lower shoe.

AU'I'I'IE T. FERRIS.

